Reduction-gear for marine steam-turbines.



.1. F METTEN.

REDUCTION GEAR FOR MARiNE STEAM TURBINES. APPLICATION FILED NOV.14,1916- Patented July 24,1917.

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INVENTOR J r w X7 HUM Hi 1. F. METTEN. REDUCTION GEAR FOR MARINE STEAMTURBINES.

APPLICATION FILED NOV. 14,1916- Patented July. 2 1917.

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JOHN F. ME'ITEN, OF PHILADELPHIA, PENNSYLVANIA,'ASSIGNOR TO THE WILLIAMCRAMP & SONS SHIP & ENGINE BUILDING COMPANY, A CORPORATION OF PENN-SYLVANIA.

REDUCTION -GEAR FOR MARINE STEAM-TURBIN ES.

Specification of Letters Patent.

Patented July 2%, 1917..

Application filed November 14, 1916. Serial No. 131,210.

To all whom it may concern:

Be it known that I, J OHN F. METTEN, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inReduction- Gears for Marine Steam-Turbines, of which the following is aspecification.

This invention relates to reduction gear mechanism and particularly tosuch mechanism for use between marine steam turbines and the propellershaft which they drive. It is especially applicable to war vessels ofhigh power wherein it is desirable to keep the power per pinion as lowas possible.

The object of the invention is to provide a gear casing which may berigid with the turbine casings, thus joining all the elements of thepropeller drive into one unitary construction. It is also an object ofthe invention to provide a novel arrangement of pinion bearings andmeans for supporting them so that there will be ample bearing surfaceand enabling each of the driving pinions to be readily accessible andremovable without interfering with the operation of the others.

In one arrangement specifically shown herein, high and low pressureturbines in steam series are located forward of the gear casing and eachdriving a pinion, the pinions meshing with a gear on the propellershaft. A similar arrangement of turbines is located aft of the gearcasing driving two other pinions.

In the accompanying drawings,

Figure l is a plan view of an installation embodying this invention;

Fig. 2 is a view in side elevation;

Fig. 3 is a section on the line 33 of Figs. 1 and 2; s

Fig. 4: is a section on the line H of Figs. 1 and 2;

Fig. 5 is an end elevation of the gear box; and

Fig. 6 is a section on the line 6-6 of Fig. l.

In the embodiment of the invention shown, the pinions 1, 2, 3, 4 meshwith a common gear 5 connected through flange coupling 6 to thepropeller shaft 6. Pin ions 1 and 2 are driven respectively by high andlow pressure turbines 1 and 2 in steam series attached to the forwardend of the gear box 7 through intermediate boxes 8 and 9. Similarlypinions 3 and 4 are driven by high and low pressure turbines 3 and 1attached to the after end of the gearbox 7 through intermediate boxes 10and 11. These intermediate boxes 8, 9, 10 and 11 are bolted to the gearbox and are provided with flanges 12 for bolting to the turbine caslngs.

In the apparatus shown, the pinions are all of the same size andinterchangeable, but may be of different sizes to suit any particularrequirement of turbines. The pinions have separated tooth sections andbetween the sections are provided with cen ter bearings (see Fig. 3).These bearings are carried on a yoke 13 cast integral with the gear box7 and passing between the forward and after sections of the gear wheel 5and beneath the flange connection 14: be tween said gear wheel sections,end bearings of the pinions are supported in end walls 15 and 16 alsocast integral with the gear case. The end bearings for the gear wheel 5are additionally strengthened by end covers 18 at either end whichtiethe end walls 15 and 16 together and the entire gear box is providedwith a cover plate 19 fastened rigidly in place to act as a stiffener.

Along the lower part of each side the gear box is formed of a hollowbox-like construction 7 (see Figs. 3' and a) to additionally strengthenthe constructions. These reinforcing and stiffening means provide a gearbox which with a minimum of material 1s strong enough to act as a centernucleus for the turbine units attached to it through boxes 8, 9, l0 and11. All the driving ele ments for a single shaft are thereby boundtogether in one unitary construction. The various parts are firmly boundin fixed relation and do not shift or cant out of alinement as is oftenthe case where the different parts of the drive are separately mounted.

The pinion center caps 20, 21 and the end caps 22, 22 and 23, 23 can beremoved independently for getting to the bearing brasses 20, 21, 22, 23,which are split horizontally. Pinion covers 2 1, 25 are alsoindependently removable for inspection of the pinions. Any one of thefour pinions can be taken out without interfering with the others. Theexposed caps of the center bearings are advantageous in permitting thebearing temperatures to be readily deter,- mined by feeling, which isnotthe case in the usual two pinion design. The main gear bearings areaccessible in'the usual way by having caps 26, 27 removableindependently of the end covers.

In the construction shown the driving pinions are supported in themiddle as well as at their ends and ample and well distributed bearingsurface is thus provided. The reinforcing and stiffening web used tosupport the central pinion bearings is also advan: tageous in furtherstrengthening the entire gearbox to serve as a center of attachment forthe turbine casings. The removable stay 1 bolt lends to the constructionall the advantages of a completely closed center web and at the sametime permits the ready insertion and removal of the main gear 5 bysimply removing end plates 18 and bearing caps 26 and disconnecting thepropeller coupling.

The pinion mountings between recesses 1n the gearbox and the caps 20 to25 render the pinions and their bearings readily ac cessible forinspection and repair and any pinion may be removed without interferingwith the other pinion inany way. The vari ous elements of the wholeinstallation are fitted and cooperate together to form a solid compactstructure serving as a center of attachment for the driving units andrendering all parts of the apparatus readily accessible and removable.In arranging the pinions from the fore and aft turbines to overlapinstead of being end for end, the con struction is rendered more compactwith a longitudinal saving of space equal to the length of one pinion.Since each set of turbines has its pinions on a common diameter throughthe center of the gear 5, either the forward or after set can be cut outat lower powers and still'give a completely balanced drive. i

It is apparent that a different arrangement of the driving units may beresorted to. For instance, 1 and 2 can be high pressure turbines,respectively, connected in series to 3 and 4 and either set may be cutout and a balanced drive produced. It is also evi-' dent that adifferent size or proportioning of parts may be used to accommodate theinstallation to the varying demands of service. The invention is notconfined to the particular embodiment shown and described, but isintended to include such modifications thereof as fall within the scopeof the appended claims.

Having thus described my invention, I declare that what I claim as newand desire to secure by Letters Patent is: p

1. In a reduction gear for marine turbine installation, a four pinionarrangement having two of the pinions driven by turbines located onforward side of gear casing and yrality of driving units geared thereto,

combination with a gear case,

formed in the ear casin removable sta'in means, and end bearings carriedin the end walls of thegear casing.

3. A reduction gear for niarii'ie purposes having four pinions, two ofwhich are driven ,bv high and low pressure turbines on forward side, andtwo by high and low pres sure turbines on after side of gear case andseparate boxes for connecting said turbines to said gear casing.

4. In a marine turbine installation, the combination with a reductiongear, of a pluleaci unit having a separate pinion, and bearings for saidpinions rendering each of them independently removable.

5. Inamarine turbine installation, the

combinationwith a gear box, of driving turbines forward and aft of saidgear case, re-

movable bearings fastened to each side of said gear case for removablysupporting the driving pinions, and a gear intermediate of said boxdriven by said pinions,

6. Ina marine turbine installation, the

of driving turbines forward and aft of said gear case, a gear anddriving pinions separated into separate toothed sections, and bearingsfor said pinions between said sections.

7. In a marine turbine installation, the combination with a gear case,of driving turbines forward and aft of said gear case, a gear anddriving pinions separated into separate toothed sections, bearings forsaid pinions between said sections, and a transverse stifiening websupporting said bearings between said Sections.

8. In a marine turbine installation, a reduction gear mechanismcomprising a gear case, driving turbines forward and aft thereof,bearings carried bythe sides of said gear case for removably supportingthe driving pinions, and removable bearings carried by the. ends of saidgear case for removably supporting the propeller shaft gear.

9. In a marine turbine installation, the combination with a gear case,driving turbines forward and aft thereof, end and cenpropeller shaftgear.

turbine installation, the

10. In a marlne comb nation with a gear case, of turbines forward andaft of said gear case,,and means rigidly fastening the casings of saidturbines to said gear case to form one unitary construction.

11. In a marine turbine installation, a reduction gear box havinglongitudinal stiffen ing means, driving turbines forward and aft of saidgear case, and intermediate conneeting boxes fastened to said gear caseand to the casings of said turbines to produce a rigid unitaryconstruction.

12. In a marine turbine installation, the combination with a gear case,of turbines located forward and aft of said case, pinions driven by saidturbines, bearings for said pinions in the ends of said gear case, andspecial bearings for said pinions intermediate the ends of said gearcase. A

13. In a marine turbine installation, a reduction gear box having endbearings for the driving pinions, and an intermediate stiffening websupporting middle bearings for said pinions.

14. In a reduction gear mechanism for a marine turbine installation, agear case having recesses on its side for supporting pinion bearings,and removable caps holding said pinions in said bearings and fastened tothe sides of said case.

15. In a reduction gear mechanism for a marine turbine installation, agear case having end bearings in its end walls integral with said gearcase, and center pinion bearings supported by a transverse yoke castintegral with said gear case.

16. A reduction gear case for a marine turbine installation comprisingend walls carrying bearings, and an intermediate stifiening web castintegral with said box and carrying center bearings.

17. A reduction gear case for a marine turbine installation comprisingend walls, longitudinal stiffening means for the side walls, and anintermediate stiffening Web cast integral with the gear case.

18. A reduction gear case for a marine turbine installation comprisingend walls, longitudinal stifiening means for the side Walls, a centralstiffening web, and bearings on the sides of said gear case supported bysaild end walls and said central stifiening we 19. A reduction gear casefor a marine turbine installation comprising end Walls and side Walls,longitudinal stiffening means for said side walls, and separate boxes atthe ends of said stiffening means for connecting the driving turbinecasings to said gear case.

20. In a marine turbine installation, the combination with a mainpropeller shaft gear of turbine driving units on different levelsforward of said gear and turbine driving units on different levels aftof said gear.

JOHN F. METTEN.

copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. G.

